An image pickup apparatus such as a digital still camera or a digital video camera is equipped with a lens-barrel.
Such a lens-barrel has, on a position of a front of image pickup device for picking up an image of a subject, a lens that directs the image of subject toward the image pickup device, a lens frame that holds the lens and is provided as to be movable along a guide shaft extending along an optical axis of this lens, and a drive mechanism for moving the lens frame along the optical axis, in such a configuration that these lens, lens frame, and drive mechanism are arranged in the lens-barrel.
As such a drive mechanism, a lens-barrel employing a linear motor has been proposed (see Japanese Patent Application Publication No. Hei 11-150972).
That is, in this lens-barrel, a magnetic circuit configured by a magnet and a yoke is equipped to a barrel as a fixed part, and a coil is equipped to a lens frame as a movable part, in which passing an electric current through the coil allows to be generated magnetic interaction between the coil and the magnetic circuit, thereby enabling the lens frame to be moved along an optical axis.